1. Field of the Invention
The present invention generally relates to hard-backed lampshades and, more particularly, to improving the light reflectivity of such lampshade without sacrificing the light transmissivity through such lampshades, and without sacrificing the structural strength thereof.
2. Description of the Related Art
Lampshades for screening light from light bulbs have been made of a variety of materials. A hard-backed lampshade includes a self-supporting backing member, with or without a fabric material laminated thereon. A soft-backed lampshade includes a fabric material stretched taut over a wire frame.
For hard-backed lampshades, with which this invention is concerned, the backing member has been made of semi-rigid paper, such as opaque boxboard or translucent vegetable paper. However, opaque boxboard is a relatively poor light reflector. Vegetable paper also does not reflect light well and, in addition, does not allow light to be uniformly transmitted therethrough due to its irregular translucent characteristics. Unless chemically treated, paper shades pose a fire hazard.
Hard-backed lampshades have also been made of high-impact polystyrene ("HIPS") which contains butydene to allow the normally rigid styrene to be easily bent without cracking into a standard frusto-conical shape for the lampshade. The thickness of the known HIPS shades lies between 12-15 mils.
Although generally satisfactory for their intended purpose, the known HIPS shades have certain drawbacks. Thus, the presence of the butydene, as well as the thickness of the shade, act to block light from being transmitted through the lampshade. Also, the presence of the butydene renders the inner surface of the lampshade irregular, that is, not smooth, so that light is not efficiently reflected from this roughened surface. Unless chemically treated, any fabric laminated onto the HIPS shade represents a fire safety risk.